<!DOCTYPE html>
<html>
	<head>
		<meta name="viewport"
			content="width=device-width,initial-scale=1.0,maximum-scale=1.0,minimum-scale=1.0,user-scalable=no">
		<meta charset="utf-8" />
		<title></title>
	</head>
	<body>
		<div class="box"></div>
	</body>
</html>
<style>
	html{
		font-size: 26.66667vw;
	}
	/* 屏幕尺寸375px
		1rem = 100px */
	.box {
		width: 1rem;
		height: 300px;
		background-color: red;
	}
</style>